The lore of the Warcraft universe is huge. It's all there if you want to explore it. I've played SWTOR and in no way, shape or form did I find that they did the story any better at all. Same goes for GW2.

For you to enjoy WoW you have to accept it for what it is, not expect it to be something it's not. Is it a cutting edge, innovative, graphically superior game? No. WoW is approaching it's tenth anniversary and the engine is now looking tired. Is it an overall solid experience, and the absolute best at what it does? Yes. The whole experience is very slick and they have made a huge amount of changes in the last 2-3 years to make things clearer and more approachable to new players.

GW2 made some innovations to combat and questing, but the end game mechanic is entirely different to WoW which puts people off. SWTOR put in a moral choice system, but many argue it's basically superficial.

Most of the people that have already invested substantial time in WoW in the past have at least quit once. They then try other games, only to come back because despite the innovations they eventually go back to WoW's tried and tested methods, and since it "just isn't WoW", people go back.

If you've never played WoW obviously you can take a step back and analyse each game for it's merits, and go solely on what you want. Different strokes for different folks and all that.